Evidence: In general, evidence is anything that may be presented in determining the truth about the fact in question. Evidence is that which supplies the means of arriving at the truth. Everything at the scene of crime that can be used to ascertain the fact of the crime constitute evidence. Evidence can be obtained through one or more of the five senses; seeing, hearing, feeling, smelling or testing.

         Locard's principle of exchange: 'When one object comes into contact with another, each invariably takes with itself some of the propertiies of the other'. Evidence is always present at the scene of crime of any offense. Whether or not evidence is found is another matter. That it is not found does not prove its absence. Failure to find evidence at the scene of crime may be due among other things to faulty protection, careless search, inadequate search, limited facilities, or ignorance.

        General Rule: 'Nothing at the scene of crime is too insignificant for proper treatment'. Cases are never lost because too much evidence has been gathered and preserved. Cases are often lost because the investigator decided that a certain article or trace is unimportant and failed to collect and preserve.

        Elements of crime The elements of crime are the aggregate of those factors necessary to constitute the particular offense. Two elements common to all the offenses are the Acts and the Intent The elements of crime of murder are that the victim named or described is dead; that the death of the victim resulted from an act or an omission of the accused; that the accused had a pre-meditated design to kill or intended to kill. Unless these elements are established through investigation, the crime of murder is not solved.

         Cases may be won or lost depending on the manner in which evidence has been collected, handled, preserved and identified. No evidence will be of any value unless it meets the requisites of proper treatment. It is also necesssary that the chain of custody be maintained. If the possession of the evidence is unaccountable for a moment the evidence is rendered inadmissible. If the possession cannot be established, it is assumed that the articles has been altered or could have been altered.

         Evidence can be easily destroyed intentionally or unintentionally, by permiting the persons to wander about the scene unless it has been photographed, sketched and searched. The untampered scene of crime can reveal the story of what occured there. If the crime scene has been tampered with, erroneous conclusion may be drawn and the crime may never be solved. Protection of scene of crime is not only against curious bystander but against curious officials as well. Too often the investigator is confronted with a hord of curious officials in and out of uniform would unintentionally destroy any traces present

         The step involves a preliminary survey of the crime scene. During the initial overview nothing is touched, pickedup or moved untill it has been photographed, sketched and minutely described as to the location, condition and any other pertinent observation. The search of the crime scene should start without pre-concieved notions of what happened, how it happened and who might have done it. What he finds and where he finds it should be the basis of his thinking. Starting an investigation with a preconceived idea will lead an investigtor to look for those things which establish his preconceived idea. The search commander should mark all evidence for purpose of identification. Nothing at the scene should be moved without the clearance from such commander.